Stopwatch

What is an online stopwatch?

An online stopwatch is a timer that counts upward from zero to measure how long something takes, running directly in your web browser with no app to install. You press start, and the display ticks up in hours, minutes, seconds, and hundredths of a second until you stop it. Unlike a countdown timer, which starts from a set duration and counts down to zero, a stopwatch starts at zero and counts up, so it answers the question "how much time has passed?" It's the digital version of the handheld stopwatch a coach or referee uses to time a race.

How to use the stopwatch

Timing something takes just a couple of clicks, and you can record laps along the way:

1. Press Start to begin counting up from zero in real time.
2. Tap Lap while it runs to record a split — the table shows each lap's own time and the running total.
3. Use Pause to freeze the clock and Resume to continue from exactly where you left off.
4. Press Reset to clear the time and laps back to zero, or Copy laps to copy your full lap list.

What are lap and split times?

A lap time is how long a single segment took — the time elapsed since your previous lap. A split (or total) time is the cumulative time from the start through that lap. For example, if you tap Lap at 0:30, 1:05, and 1:40, the lap times are 0:30, 0:35, and 0:35, while the split times are 0:30, 1:05, and 1:40. Lap times let you compare each segment against the others, which is exactly what runners and swimmers use to track pacing across a workout.

Stopwatch vs. countdown timer

A stopwatch and a countdown timer are opposites. A stopwatch starts at zero and counts up, measuring how long an activity of unknown length takes; it answers "how much time has passed?" A countdown timer starts from a duration you set and counts down to zero, alerting you when the time runs out; it answers "how much time is left?" Use a stopwatch to time something open-ended like a run or a task, and a countdown timer to limit an activity to a fixed length.

Will the stopwatch stay accurate in a background tab?

Yes. The stopwatch measures real clock time using timestamps rather than counting one tick per second, so the elapsed time stays accurate even if your browser slows down or throttles an inactive background tab. When you switch back to the tab, the display catches up to reflect the actual time that has passed since you started or last resumed.

Why use this online stopwatch?

• Counts up live with a large, easy-to-read display down to a hundredth of a second.
• Record unlimited lap and split times in a clean table as you go.
• Start, pause, resume, and reset controls keep you in full control of the clock.
• Copy your entire lap list with one click for notes or spreadsheets.
• Stays accurate using real clock time, even when the browser throttles a background tab.
• Runs entirely in your browser — no app to install and nothing is uploaded.
• 100% free with no ads, sign-up, or limits.

Frequently asked questions